Memory cards are commonly used in various kinds of electronic equipment in the communications and computer industries in areas such as telecommunication, network routing, personal computers, laptop computers, and a host of specialized equipment. These memory cards are presently arranged within three types, Type I, Type II, and Type III, as defined by Personal Computer Memory Card International Association (PCMCIA) and Japan Electronics Industry Development Association (JEIDA), the industry standards. The Type I cards have the lowest profile, or height and typically contain random access memory (RAM), but may contain proprietary programs and other data in read only memory (ROM) format as well. The Type II cards have a slightly higher profile than the Type I card and typically contain electronic device assemblies such as FAX/MODEM units for communications, and may contain RAM or ROM as well. The Type III cards are high profile, being about twice as high as the Type II cards and typically contain hard disc drive units, but may contain other electronic devices that require the increased volume offered by the high profile Type III cards.
In the equipment that utilize these memory cards, space within the equipment is minimized to provide a smaller and lighter end product. This, of course, means that the connectors that interconnect the memory cards to the electronic equipment must also be as small and light as possible. These connectors are usually packaged to receive two memory cards concurrently, one stacked above the other. Such a memory card connector is show in FIG. 1 and identified as 10. The connector 10 includes an upper pin header 12 and a lower pin header 14 in stacked arrangement and secured together by means of stacking clips 16 that are forced into slots in the two pin headers. Each of the two pin headers includes electrical pin contacts therein having leads 18 that extend outwardly and downwardly to interconnect with contacts on a circuit board to which the connector 10 is to be mounted. The electrical pin contacts interconnect to mating contacts in the memory cards when the memory cards, not shown, are inserted into the connector 10. The connector 10 includes upper and lower right side walls 20 and 22, respectively, that extend outwardly from the right ends of the upper and lower pin headers 12 and 14, respectively, as shown in FIG. 1. Similarly, upper and lower left side walls 24 and 26 extend outwardly from the left end of the upper and lower pin headers 12 and 14, respectively, as shown in FIG. 1. A lower lateral member 28 extends between and is attached to the two lower side walls 22 and 26, and an upper lateral member 30 extends between and is attached to the two upper side walls 20 and 24. A track is formed in the inside surface of each of the side walls 20, 22, 24, and 26 thereby forming an upper card receiving cavity 34 and a lower card receiving cavity 36, one above the other. Each of these two cavities is sized to receive either a Type I or Type II memory card concurrently with the other cavity. Additionally, the lower cavity 36 can receive a Type III high profile memory card, however, a portion of the Type III card must necessarily intrude into the upper cavity 34 thereby preventing use of that cavity by another memory card. Lwee U.S. Pat. No. 5,299,089 which issued Mar. 29, 1994 discloses a memory card connector capable of concurrently receiving both a Type I or II card in one cavity and a Type III card in another cavity. However, the overall height of the connector is increased to accommodate the additional height of the Type III card. This overall height increase in the connector adversely affects the available usable space when the equipment that contains the connector does not require a Type III memory card. Additionally, as the industry moves toward faster data transfer rates, these memory card connectors will require suitable shielding to prevent crosstalk between the two memory cards. It is difficult for the present prior art memory card connectors to accommodate such shielding.
What is needed is a memory card connector that can either accommodate two Type I or Type II cards in two separate cavities or can accommodate one Type I or Type II card in one of the cavities and concurrently a Type III card in the other cavity while increasing the overall height of the connector and memory card assembly a minimum amount. Further, the memory card connector should include shielding that inhibits crosstalk between the two memory cards that are contained in the two cavities.